Exercise is one of the surprising things that influence your blood pressure levels. While most forms of exercise are good for lowering blood pressure, a 2023 meta-analysis of 270 randomised controlled trials including almost 16,000 participants, published in the British Journal of Sports Medicine, found that a few particular exercises beat out the rest.
An isometric leg extension was one of the exercises that had a significant blood-pressure-lowering effect on the participants. It was effective at lowering systolic blood pressure, which is the maximum pressure in your artery walls when your heart is beating. Diastolic blood pressure is the rate of pressure in your artery walls when your heart is resting in between beats. Both of these readings were found to be lowered by doing isometric, also known as static, leg extensions.
An isometric leg extension is typically done with a leg extension/leg curl machine or weights. Before we get into how you can perform the exercise at a gym or at home, let’s take a look at what isometric exercises are. When you’re doing an isometric exercise, you’re essentially holding an exercise pose for a few seconds or minutes at a time, while contracting the muscle/muscles in question. Typical examples include planks, wall sits (which were actually the most effective in reducing blood pressure, per the study), and a static split squat.
How do isometric exercises lower your blood pressure?
While the researchers behind the 2023 study aren’t entirely sure how certain exercises performed better than others when it came to lowering resting blood pressure, some experts have theories. The study compared isometric exercises — like static weighted leg extensions, isometric hand grips, and wall sits — with other forms of exercise, like aerobic training, resistance training, high-intensity interval training (HIIT), and combined training.
As explained by professor of exercise and sports science at the University of New England in Australia, Neil Smart (via WebMD), squeezing your muscles during an isometric exercise constricts the surrounding blood vessels, leading to a reduced blood flow to the area. Holding that squeeze also boosts the presence of oxygen-inhibiting anaerobic metabolites in your system. “The body doesn’t like them [anaerobic metabolites]. As soon as you stop squeezing, blood flow will be normalized and then enhanced in an attempt to clear up this mess that’s been created [in the area],” explained Smart.
The sudden rush of blood flow to the area boosts vasodilation (meaning, it helps dilate your blood vessels). Dilated blood vessels mean a smoother flow of blood. This could be how isometric exercises lead to reduced resting blood pressure. Now let’s take a look at how you can do an isometric leg extension, and some other things to consider while doing isometric workouts for blood pressure.
How to do a static leg extension
If you’re enrolled in a gym and have access to a standard leg extension/leg curl machine, then all you have to do is take up the proper position at the machine — sitting down with a strong core and supported spine — before slipping your legs under the weighted pads and lifting them up to a 60 degree or 45-degree angle. Hold the position while contracting your leg muscles for 45 seconds, before resting for a minute.
If you’re doing the exercise at home, you’ll need something stable and low to the ground — like an exercise bench — that you can tie a resistance band around. After putting the band around your ankle, push upward against the band, hold for a few seconds, rest, and repeat. You can also use ankle weights or a medicine ball. Simply sit with your back upright on a chair or exercise bench (you can hold on to the sides of the bench with your hands for support), lift your legs up and hold for 45 seconds before resting for a minute. With a medicine ball, make sure to balance the ball properly between your ankles and squeeze as you lift up.
The goal is to contract your leg muscles (particularly your quads) and hold them in that state for a while. It is important to note, however, that lowering blood pressure is not just about exercise. Your diet, weight, alcohol consumption, smoking habits, and medications play a role too.
Important aspects of isometric exercise to think about
Fitness specialists stress the importance of remembering to breathe while performing isometric exercises. It’s natural — especially if you’re doing this kind of exercise for the first time — to hold your breath through the contraction, but this can have negative connotations for your blood pressure; It can actually spike your blood pressure response.
If you’ve never done isometric exercises before, you can easily include them in your current workout routine. However, people with existing heart conditions or really high blood pressure, like stage two hypertension or stage three (severe) hypertension — the latter of which is when one’s blood pressure is upward of 180 systolic and 120 diastolic — should consult with their doctor before doing any form of exercise.
That being said, isometric exercises are just one type of exercise that helps lower blood pressure. While isometric training was found to be the most effective, the best type of exercise for blood pressure management and overall cardiovascular health is one you’d stick to, rather than not exercising at all. This is where the enjoyment factor comes in. “Exercise is good for your heart health and health in general. It can reduce the risk of heart and circulatory diseases by up to a third,” explained senior cardiac nurse at the British Heart Foundation, Joanne Whitmore. “Aerobic exercise in particular can help the heart and circulatory system work better through lowering blood pressure. Current guidelines also encourage muscle strengthening exercises, like yoga or Pilates.”
